1.Give 2 reasons why cells divide. a.DNA overload – Too many demands on DNA b.Exchanging materials – The bigger the cell, the greater the distance oxygen, nutrients, & waste have to travel for cell to work. oxygen Carbon dioxide oxygen Carbon dioxide oxygen Carbon dioxide

2. How is a cell’s DNA like the books in a library? DNA is like a book of instructions for a cell. The bigger the cell, the more demands there will be on the DNA. The bigger the town/city, the more demands there will be for a library book. Instruction Book

3. As a cell increases in size, which increases more rapidly, its surface area or its volume? volume

4. Calculate the surface area, volume, and ratio of surface area to volume of an imaginary cubic cell measuring 4 cm on each side. 4 cm Surface Area = 4 cm x 4 cm x 6 = 96 cm 2 Volume = 4 cm x 4 cm x 4 cm = 64 cm 3 SA : V = 96:64 = 3:2

Connecting Concepts. Select 2 cell organelles and describe how their functions might be impaired if the cell were to become too large. Nucleus wouldn’t be able to control all cell activities if cell got too big. Ribosomes wouldn’t be able to make enough proteins for cell if cell got too big. Mitochondria wouldn’t be able to supply enough energy/power for cell if cell got too big. Endoplasmic reticulum wouldn’t be able to make enough lipids and proteins if cell got to big.